Depomed, Inc. has filed a patent infringement lawsuit in the United States District Court for the District of New Jersey against Banner Pharmacaps Inc. and Watson Laboratories, Inc. Banner Pharmacaps has filed an Abbreviated New Drug Application (ANDA) with the FDA to market generic Zipsor (diclofenac potassium) 25mg capsules and has granted to Watson Laboratories exclusive rights to the proposed generic product.

The lawsuit claims infringement of Depomed's five US patents listed for Zipsor in the FDA's Orange Book, the last of which expires in 2029, by the defendants' proposed generic product.

Depomed has received a Paragraph IV certification notice from Banner Pharmacaps alleging that Depomed's patents will not be infringed by the proposed generic product, or the patents are invalid or unenforceable.  Depomed commenced the lawsuit within the 45 days required to automatically stay, or bar, the FDA from approving the Zipsor ANDA for 30 months from the date of receipt by Depomed of the notice (December 2015) or until a district court decision that is adverse to the patents, whichever may occur earlier.

Depomed, Inc. is a specialty pharmaceutical company with three approved and marketed products. Gralise (gabapentin) is a once-daily treatment approved for the management of postherpetic neuralgia (PHN). Zipsor (diclofenac potassium) liquid filled capsules is a non-steroidal anti-inflammatory drug (NSAID) indicated for relief of mild to moderate acute pain in adults. Glumetza (metformin hydrochloride extended release tablets) is approved for use in adults with type 2 diabetes and is commercialized by Santarus, Inc. in the United States.